Augmented reality (AR) is a technology for augmenting virtual contents in the physical world. One application of the augmented reality technology is to enable users to see physical contents in the physical world and the virtual contents in the virtual world at the same time through a displaying apparatus. Generally, the physical content may be provided by an image capturing apparatus (e.g., a camera), and the virtual content may be provided by a computing apparatus. Because the physical content displayed by the displaying apparatus changes as the image capturing apparatus moves (involving changes of location and/or direction), the computing apparatus must provide the corresponding virtual content as the image capturing apparatus moves to keep the augmented reality effective. For example, if a user faces a front surface of a vase at the beginning, and the displaying apparatus displays the front surface of the vase and a front surface of a bunch of virtual flowers placed in the vase at the beginning, then the displaying apparatus must display a side surface of the vase and a side surface of the bunch of virtual flowers in real time when the user moves to another location and faces the side surface of the vase.
To enable the computing apparatus to provide the corresponding virtual content as the image capturing apparatus moves, the conventional augmented reality technology generally creates in advance a plurality of feature point maps for the physical contents of a same target that are captured by the image capturing apparatus at various locations and/or directions. When the location and/or direction of the image capturing apparatus changes, the conventional augmented reality technology uses feature points on the feature point maps to identify the current location and/or direction of the image capturing apparatus, thereby obtaining the change in the location and/or direction of the image capturing apparatus. In this way, when the image capturing apparatus moves, the conventional augmented reality technology provides the corresponding virtual content according to the change in the location and/or direction of the image capturing apparatus.
The conventional augmented reality technology is actually limited and inconvenient to a large extent. For example, a plurality of feature point maps have to be created in advance (which increases the time cost), and the physical content captured by the image capturing apparatus has to comprise enough available feature points (i.e., the space complexity of the physical content must be relatively high). Accordingly, an urgent need exists in the art to improve the aforesaid problems of the conventional augmented reality technology.